The Metro services that currently terminate on the down platform will (presumably) go into the new bay -making them the wrong side of the station for the bus stop and the multi storey car park (although the right side for the station car park).

Whelchairs/bikes/pushchairs etc. for up trains are going to have to either go round the end of the bay, or use a lift. And the island is going to be narrow, so difficult to get a wheelchair up to the other end in the rush hour, especially when half the platform are waiting for the next HS/metro rather than the one currently in the platform.

The shops will now be on only the bay platform, ditto toilets, etc. (not room to put them on the island.

In summary, I don't think it's going to work very well; but I also see no other way of getting the extra platform length in there

Wheelchairs/bikes/pushchairs etc. for up trains are going to have to either go round the end of the bay, or use a lift. And the island is going to be narrow, so difficult to get a wheelchair up to the other end in the rush hour, especially when half the platform are waiting for the next HS/metro rather than the one currently in the platform.

The shops will now be on only the bay platform, ditto toilets, etc. (not room to put them on the island.

In summary, I don't think it's going to work very well; but I also see no other way of getting the extra platform length in there

The new central platform is 'single faced' and is (as mentioned earlier) fenced off. This platform is actually wider than both current platforms, although you are correct in noting the lack of any facilities on it - save, seating and an 80 metre modern canopy. There is scope, however, for a coffee/tea kiosk near the new footbridge on this platform and the current shop on platform 1, will be able to extend into the space vacated by the soon to be demolished old footbridge. - although I understand that the owners of the very small Pumpkin shop, are unwilling to invest as such, (after all, they possess a complete monopoly at this station. The space to be soon available on platform 3 (currently platform 2), where the other end of the old footbridge remains in situ for the time being, will also be available for retail - should anyone wish to enquire.

The majority of the station buildings are indeed Grade 11 listed, however, to many, it is now seen as it's achilles heel. The ideal solution would have been to replace the London end road bridge and extend there, or even a replacement 4 platform station altogether. But there we go.